Why not point compressed air at the rails? Edit: D'oh, already suggested up-thread. Rest of my comment still stands. I'm sure even electric trains already hav

Why not point compressed air at the rails? Edit: D'oh, already suggested up-thread. Rest of my comment still stands. I'm sure even electric trains already have a compressed air system for brakes (though being UK, it might be vacuum). If you really want to get fancy, have a computer vision system looking ahead that will only turn on the air when it sees leaves.